Baking oven



Aug. 2 1927.

' C. H. RlcHEs ET AL BAKING VEN Filed March 8. 1924 2 Sheets-SheetV 1 Aug. 2, 1927.

C. H. RICHES ET AL.

BAKING OVEN Filed Maron 8. 1924 2 smmhshem 2 fia. 2.

4% /rvvaw Patented ug. 2, 1927.

UNITED STATES 1,637,427 PATENT OFFICE.

CHARLES HENRY nIcnEs, or TORONTO, AND CLARENCE WILT-AAM AIRD, OF BEANT- FORD, ONTARIO, CANADA, ASsIGNORs To THE BnANTrOnn OVEN & RACK Co. LIM- ITED, or* BRANTFORD, CANADA, A ConronATron OF THE rno'vrNCn or ONTARIO.

BAKING OVEN.

Application filedl March 8, 1924. Serial" No. 697,756.

This invention relates to a baking Oven comprising a plurality of baking chambers and a plurality of heating chambers located one above and another below eac-h baking chamber and separatedtherefrom by heat conducting bars or plates and heatstoring slabs supported thereon; the object of the invention being toy maintain a circulation of heated air through the baking and heating chambers and thus pevent steam yand gas from settling around the baking product'.

For the maintenance of this air circulation the heating chambers areconnectedwith their respective baking Chambers by vents,

r and the baking chambers are connected withY a stack by damper Controlled vents through which the heated air of any or all the baking'chambers can be exhausted. and the temperature of the baking chambersfregulated or controlled; y'

In the preferred type of oven the external walls are constructed of sheetv metal insulated by infusorial earth, mineral wool, or pulverized asbestos mixture or other heat non-conducting material and the heating and baking chambers are separated from each other by tile, soap stone, fire brick or other suitableV heat conducting and retaining material.

For an understanding. of the invention reference is to be had to the following descriptionand tothe accompanying drawings in which:

Fig.- l is a longitudinal vertical section of' the oven and,

Fig. 2 is a cross sectionalview ofthe same, showing the arrangement of baking andl heating chambers, vents, and electric heating elements, and i 'y y Fig. 3 is a plan view of the heating element. .i Y y f l The casing of theV oven consists of an oven front 1, an Oven back 2, side Walls 3 connecting the oven front and oven back, an oven top 4 and an oven bottom 5. Each of the above parts is separable from each and all of the others and is preferably a complete unit in itself so that they can be shipped in a knock down condition.

The oven which may be of any usual or preferred type and can be constructed with any desired number of baking chambers and heating chambers, is shown to consist ymerely heating chambers S, 9 and 10, these being sullicient for explaining the purpose and general principlesV of the invention. The heating chamber 19 is located at the bottom of the oven. and the baking chamberv l7 lis immediatelyabovethis heating chamber. The

baking deck 11 separating the baking cham ber 7 from the heating chamber 10 is preferably composed of fire brick'laid on heat conducting bars 1Qsupported by angle iron side rails 13 securedvto the inner. surfaces of the side Walls The top 1/1 of the baking chamber 7 is also constructed of fire brick laid on heat'conducting bars supported by angle iron side rails similar to the bars 12 andrails l?) respectively. Above the baking chamber 7 is the heating `chamber 9 and above the heating chamber 9. is the baking chamber 61 separated from the heating chamber'y9 by a baking deck 15 similar to the baking deck Y12and laid Von heat conducting bars supported on angle iron side. rails.

rThe 'top 116 of the baking chamber 6 is` similar to the top 14 of the baking chamber 7 and supported in the same manner. Above the baking chamber 6 is` a'heati-ng chamber 8. In each ofthe heating chambers 8,9 and l0' is a heating element 17. In the side walls` arey vents 1S connecting the baking chamber 7 and heating chamber 10. These vents 18 are provided with openings 19 into the bakingy chamber 7v and with openings 2O into the heating chamber. y The lower edges of the openings 19 are in substantially the same plane as the top surface of the bakingA deck 11. At the back ofthe oyen are vents 21 connecting .the baking ,chamber 7 with the heating chamber 10. The opening from'` the vent A*21 into the baking chamber 7 y is at a much higher elevation than the openings 19 and discharges heated air from the heating chamber 10 into the baking chamber 7. The heated air circulates from the vent 21 towards the front of the oven and passes through the openings 19 into the vents 18 and then through the openings 20 into the heating chamber lO'where it comes into conthe heating chamber 9 by vents 18a in the side walls and by vents 2l@L in the back wall for the same circulation as exists through the of two baking chambers 6 and 7 and three baking chamber 7 and heating chamber 10,`

The baking chamber 6 is connected with the heating chamber 8 by vents 18h inthe side walls Y vent 23 is opened to connect Vthe baking chamber with the stack, and the air, vapor, and gases then pass from the baking chamber into the stac When it is desired to draw oil' the heated air, vaEor and gases from the baking'chamber 6 t e damper controlled vent24iso ened to connect the baking chamber 6 wit the stack.l By means of the vents 23 and 24 the y heating chambers 8, 9 and 10 consists of an temperature in the 4baking chambers can be regulated' to the desired egree.

Each of the heating elements 17 in the insulated grid wound with conductor wire of high resistance and divided into sections for varying the heat, and as is usual infeectric heating elements of this class t-hecircuit of the current'is controlled through these sections by switches 29.l v

The baking deck 11` is heated by radiation from the heating element 17 in the yheating chamber 10 and the top 14 ofthe baking chamber 7 is heated by radiation from the heater element 17 in the heating chamber 9. The airheated in the chamber 10 lcirculates through the vent 21 into the baking chamber 7 and from the baking chamber 7 returns through they vents 18 to the heatingchamber 10. Likewise the decks 15 and 16 are heated b radiationfrom the heating element in tfie heating chamber 9. The air heated in the heating chamber 9 circulates through the vent v21a into the baking n chambery 6 and from thel baking chamber 6 returns through the vents 18a to the heating chamber 9. The heated. air in the heating chamber 8 circulates through they vents 18b into the baking chamber 6 due to the `presy sure resulting from the increased temperature of the air in the heating chamber 8. Thus, by conduction through the baking decks, and, by convection through the circulation of the air and gases 'within the baking chamber, the full heating power of the element is utilized in cooking the substance of the baking product.

The oven door is provided with a damper controlled ventilator 27 for maintaining a circulation of air through the baking and heating chambers, which circulation prevents the baking product becoming heavy and sodden. In making bread the flour is required to absorb sufficient water for the expansion of the gluten to its fullest extent. Vhen the dough is introduced into the oven the air in the baking chamber is relativel dry. The heat of the oven causes the vaporlzation of the water and the liberation of the gases from the dough but the circulation of the heated air through the vents causes the rapid movement of the gasesand vapor so that when the bakingis completed the outside of the loaf has a .golden 'brown crust with a. peculiar pungent odor.

Having thus fully described our invention whatwe claim as new and desire to secure by Letters Patent is:

A baking oven comprising a baking chamber, two heating chambers, vone located below 'and separated from the baking chamber by the baking deck and the other locatedA above the baking chamber and separated from it, an electric heating element 1n each heating chamber, a vent connecting the baking chamber with the heating chamber below it and provided with an opening into the baking chamber the lower edge of which is substantially in the same plane as the top surface of the baking deck,v for maintaining a circulation of air from the baking chamber tothe heating chamber, and a vent connecti g the heating chamber withthe baking clamberabove it having an opening into the bakng chamber above the level of the first-mentioned vent for the circulation of the heated air from the heating chamber to the bakingv chamber.

Signed atthe vsaid city of Toronto this twenty-first day of February, A. D. 1924.

CHARLES H. RICHES., CLARENCEV WILLIAM 'AIR D. 

